The first factorial number greater than 1 billion. The largest 10-digit factorial number.

6,240,321,451

[Math.]6,240,321,451 = (6+2+4+0+32+1+45+1)5 = 915.

6,241,474,009

[Math.]Sum of the first 397 cube numbers:

13+…+3973 = 6,241,474,009 = (1+2+…+397)2 = 79,0032.

x,yzw,abc,def

[Math.] For any x,yzw = 1000 to 9999, there are always six 6-digit numbers abc,edf such that x,yzw +abc,def is equal to one of 6 digit-rotations of 142,857 and the number x,yzw,abc,def is a multiple of 142,857.

For any x,yzw = 1000 to 9999, there are always twelve 6-digit numbers abc,edf such that x,yzw +abc,def is equal to one of 12 digit-rotations of 076,923 or 153,846 and the number x,yzw,abc,def is a multiple of 76,923.